Normative ranges of biventricular volumes and function in healthy term newborns

BACKGROUND

Cardiovascular magnetic resonance (CMR) is increasingly used in newborns with congenital heart disease. However, reporting on ventricular volumes and mass is hindered by an absence of normative data in this population.

DESIGN/METHODS

Healthy term (37-41 weeks gestation) newborns underwent non-sedated, free-breathing CMR within the first week of life using the 'feed and wrap' technique. End-diastolic volume (EDV), end-systolic volume (ESV) stroke volume (SV) and ejection fraction (EF) were calculated for both left ventricle (LV) and right ventricle (RV). Papillary muscles were separately contoured and included in the myocardial volume. Myocardial mass was calculated by multiplying myocardial volume by 1.05 g/ml. All data were indexed to weight and body surface area (BSA). Inter-observer variability (IOV) was performed on data from 10 randomly chosen infants.

RESULTS

Twenty healthy newborns (65% male) with a mean (SD) birth weight of 3.54 (0.46) kg and BSA of 0.23 (0.02) m2 were included. Normative LV parameters were indexed EDV 39.0 (4.1) ml/m2, ESV 14.5 (2.5) ml/m2 and ejection fraction (EF) 63.2 (3.4)%. Normative RV indexed EDV, ESV and EF were 47.4 (4.5) ml/m2, 22.6 (2.9) ml/m2 and 52.5 (3.3)% respectively. Mean LV and RV indexed mass were 26.4 (2.8) g/m2 and 12.5 (2.0) g/m2, respectively. There was no difference in ventricular volumes by gender. IOV was excellent with an intra-class coefficient > 0.95 except for RV mass (0.94).

CONCLUSION

This study provides normative data on LV and RV parameters in healthy newborns, providing a novel resource for comparison with newborns with structural and functional heart disease.

Survival After Intervention for Single-Ventricle Heart Disease Over 15 Years at a Single Institution

BACKGROUND

Children with single-ventricle (SV) heart disease possess a spectrum of heart malformations, yet progress through similar hemodynamic states, suggesting differences in outcomes are related to fundamental morphologic differences, patient characteristics, or procedural pathways. We sought to provide a holistic overview of survival after intervention for SV heart disease at our institution.

METHODS

SV heart disease was defined as patients born with a hypoplastic or dysfunctional ventricle with uncertain or unacceptable candidacy for a 2-ventricle circulation. Patients were stratified into 8 diagnostic groups and 11 procedural categories based on the initial interventional procedure.

RESULTS

Between 2005 and 2020, 381 patients born with SV heart disease underwent intervention at our institution. Ten-year survival was highest for patients with double inlet left ventricle (89% ± 7%) and lowest for patients with hypoplastic left heart syndrome (55% ± 5%). Initial palliation with less invasive procedures, such as ductal stent (4-year: 100%) or pulmonary artery banding (10-year: 95% ± 5%), demonstrated superior survival compared with more invasive procedures such as the Norwood procedure (10-year: 59% ± 4%). Survival of patients who achieved a biventricular circulation was superior to patients who remained with SV physiology (10-year: 87% ± 5% vs 63% ± 3%, P = .04). In a multivariable analysis, chromosomal/syndromic abnormality, lower weight, hybrid Norwood procedure, nonleft ventricular dominance, and earlier year of operation were risk factors for death.

CONCLUSIONS

Survival differences in patients with SV heart disease were related primarily to underlying cardiac anatomy, patient characteristics, and procedural complexity. Left ventricular dominance, more recent intervention, and attainment of a 2-ventricle circulation were associated with improved survival.

Management of the Borderline Left Heart and Alternatives to Fontan

Management of borderline left heart can be divided into single ventricle and biventricular repair strategies. Recently, the strategy of left heart recruitment has been applied to select patients. Left heart recruitment strategies and alternatives to Fontan circulation are reviewed. The criteria utilized for decision-making include size and function of left heart structures as well as hemodynamics measured by cardiac catheterization.

Considerations for Biventricular Conversion of Fontan Circulation

Despite significant improvements in the management of Fontan circulation in patients with single ventricle physiology, long-term outcomes continue to be suboptimal. Conversion to biventricular circulation is increasingly gaining popularity, particularly in the subset of patients who are not ideal Fontan candidates. Meticulous image-guided planning, extensive preoperative discussions, and a team-based approach are required for successful execution of complex biventricular conversion. A segmental approach to the anatomy of the heart defect allows methodical planning of the technique of biventricular conversion. Ventricular size and function continue to be the Achilles heel of successful biventricular repair. Long-term studies comparing outcomes in patients converted to biventricular circulation to those in patients with Fontan physiology are required to appropriately tailor management approaches to an individual patient.

Reoperations After Repair for Atrioventricular Septal Defects: >25 Years Experience at a Single Center

Our aim was to evaluate the total burden of reoperations after previous repair for atrioventricular septal defects, including long-term survival and identify risk factors for reoperation. All patients with surgical correction for atrioventricular septal defect (AVSD) 1993- 2020 underwent a follow-up in October 2020. Clinical data were obtained by retrospective review and evaluated with Kaplan-Meier and competing risk analysis. Of 477 patients who underwent initial repair, 53 patients (11.1%) underwent a total of 82 reoperations. The perioperative mortality at reoperation was 3.8% (2/53). There were no late deaths (0/51) during follow-up. In patients requiring reoperation for left atrioventricular valve regurgitation, a re-repair was performed in 90% (26/29) at first attempt. Estimated overall survival was 96.2 ± 2.6% (95% CI 91.2-100) in the Any reoperation group and 96.7 ± 0.9% (95% CI 94.9-98.5) in the No reoperation group at 20 years (P = 0.80). The cumulative incidence function of Any reoperation (with death as competing risk) was 13.0% (95% CI 9.4-16.5) at 20 years. Independent risk factors for Any reoperation included severe mitral regurgitation after primary repair (HR 40.7; 95% CI 14.9-111; P < 0.001). The risk of perioperative mortality in AVSD patients undergoing reoperation was low in the present study. Long-term survival was very good and not significantly different when compared to patients who did not need reoperation. Re-repair for left atrioventricular valve regurgitation was possible in most cases and showed long-term durability. Our data suggest that reoperations after primary repair of AVSD have very good long-term outcomes when performed at a high-volume pediatric cardiac surgery center.

Biventricular Conversion for Hypoplastic Left Heart Variants: An Update

Ongoing concerns with single-ventricle palliation morbidity and poor outcomes from primary biventricular strategies for neonates with borderline left heart structures have led some centers to attempt alternative strategies to obviate the need for ultimate Fontan palliation and limit the risk to the child during the vulnerable neonatal period. In certain patients who are traditionally palliated toward single-ventricle circulation, biventricular circulation is possible. This review aims to delineate the current knowledge regarding converting certain patients with borderline left heart structures from single-ventricle palliation toward biventricular circulation.

Impact of 3D Printing on Short-Term Outcomes of Biventricular Conversion From Single Ventricular Palliation for the Complex Congenital Heart Defects

Background: Although Fontan palliation seems to be inevitable for many patients with complex congenital heart defects (CHDs), candidates with appropriate conditions could be selected for biventricular conversion. We aimed to summarize our single-center experience in patient selection, surgical strategies, and early outcomes in biventricular conversion for the complex CHD.

Methods: From April 2017 to June 2021, we reviewed 23 cases with complex CHD who underwent biventricular conversion. Patients were divided into two groups according to the development of the ventricles: balanced ventricular group (15 cases) and imbalanced ventricular group (8 cases). Early and short-term outcomes during the 30.2 months (range, 4.2–49.8 months) follow-up period were compared.

Results: The overall mortality rate was 4.3% with one death case. In the balanced ventricular group, 6 cases received 3D printing for pre-operational evaluation. One case died because of heart failure in the early postoperative period. One case received reoperation due to the obstruction of the superior vena cava. In the imbalanced ventricular group, the mean left ventricular end-diastolic volume was (33.6 ± 2.1) ml/m2, the mean left ventricular end-diastolic pressure was 9.1 ± 1.9 mmHg, and 4 cases received 3D printing. No death occurred while one case implanted a pacemaker due to a third-degree atrioventricular block. The pre-operational evaluation and surgery simulation with a 3D printing model helped to reduce bypass time in the balanced group (p &lt; 0.05), and reduced both bypass and aorta clamp time in the imbalanced group (p &lt; 0.05). All patients presented great cardiac function in the follow-up period.

Conclusion: Comprehensive evaluation, especially 3D printing technique, was conducive to finding the appropriate cases for biventricular conversion and significantly reduced surgery time. Biventricular conversion in selected patients led to promising clinical outcomes, albeit unverified long-term results.

Single Ventricle-A Comprehensive Review

In this paper, the author enumerates cardiac defects with a functionally single ventricle, summarizes single ventricle physiology, presents a summary of management strategies to address the single ventricle defects, goes over the steps of staged total cavo-pulmonary connection, cites the prevalence of inter-stage mortality, names the causes of inter-stage mortality, discusses strategies to address the inter-stage mortality, reviews post-Fontan issues, and introduces alternative approaches to Fontan circulation.

Common atrioventricular valve surgery in children with functional single ventricle

OBJECTIVES

A common atrioventricular valve (CAVV) is considered to be a risk factor for early and late deaths in patients with functional single ventricle (FSV). CAVV surgery in patients with FSV is challenging and there is limited knowledge of the outcomes of CAVV repair with univentricular physiology.

METHODS

We reviewed all CAVV surgical procedures in patients with FSV who underwent univentricular palliation. End points of the study were survival after CAVV surgery and cumulative incidence of reoperation.

RESULTS

Between 1984 and 2019, 66 children with CAVV and FSV underwent single-ventricle palliation, of whom 45.5% (30/66) required CAVV surgery. Indication for surgery was moderate CAVV regurgitation in 40% (12/30) and severe CAVV regurgitation in 60% (18/30). CAVV repair was performed in 93.3% (28/30) and CAVV replacement in 6.7% (2/30). The median age and weight at surgery were 0.9 years (interquartile range 0.3-1.8) and 6.5 kg (interquartile range 3.9-8.7), respectively. Operative and late mortality were 23.3% and 8.7%, respectively. Survival and cumulative incidence of reoperation at 4 years after CAVV surgery were 68.9% [standard deviation (SD): 8.7] and 35.8% (SD: 9.1), respectively. Fontan completion was achieved in 60% (18/30). Survival at 4 years after birth was 69.7% (SD: 8.5) in 30 patients with CAVV surgery, whereas it was 83% (SD: 6.3) in 36 patients without CAVV surgery (P = 0.32).

CONCLUSIONS

CAVV surgery in patients with FSV is associated with substantial mortality and a high incidence of reoperation.

Restriction of Atrial Septal Defect Leads to Growth of Hypoplastic Ventricle in Patients with Borderline Right or Left Heart

Patients with borderline hypoplastic right or left ventricle and VSD may be candidates for either single ventricle palliation or staged ventricular recruitment (SVR) followed by eventual biventricular conversion. Components of SVR include restriction of atrial septal defects (ASD) without ventricular septal defects (VSD) closure and addition of accessory pulmonary blood flow. This study evaluated the impact of ASD restriction on ventricular growth and function. We retrospectively reviewed patients with borderline ventricular hypoplasia and VSD who underwent a staged ventricular recruitment (SVR) procedure from 2012 to June 2019. Pre- and post-recruitment MRI and echocardiogram data were compared and analyzed. We excluded cases in which we intentionally restricted VSD with simultaneous ASD restriction. Forty-six patients (41 with right-dominant ventricle, 25 with risk factors for Fontan procedure) underwent SVR at a median age of 15.1 months' (interquartile range (IQR), 7.2-37.2 months'). The median indexed ventricular end-diastolic volume, end-systolic volume, and stroke volume according to cardiac MRI significantly increased at median 11.0 months' (IQR:7.8~14.1 months') after recruitment. Among them, except 2 operative mortalities after SVR, 26 patients underwent bi-ventricular repair (56.5% including one and a half ventricle repair) at a median of 8.0 months' (IQR: 6.2-12.2 months') after recruitment. Fifteen patients await biventricular completion, and 3 patients underwent single ventricle palliation. Pulmonary blood flow (Qp) tended to increase after recruitment regardless of type of pulmonary blood flow modification without statistical significance. Six patients died at a median duration of 6.5 months' (IQR: 2.9-11.7) after SVR; 3 patients died after biventricular completion, 2 after recruitment, and 1 after returning to single ventricle palliation. All of them were considered poor Fontan candidates due to severe atrioventricular valve regurgitation, pulmonary hypertension, pulmonary vein stenosis, or airway stenosis. Restriction of the atrial septum leads to the growth of hypoplastic ventricle in patients with ventricular septal defects who undergo SVR regardless of the preoperative characteristics, and eventual biventricular repair can be performed in a subgroup of these patients. Future work is necessary to optimize timing of SVR and method of accessory pulmonary blood flow.

Development of a biventricular conversion program: A new paradigm

BACKGROUND

Borderline small ventricular size or technical issues precluding the use of both ventricles may lead to single ventricle palliation. Fontan complications have led some centers to look for alternatives to the traditional pathway. The objective of this study is to evaluate the essential philosophy and outcomes of a new biventricular (BiV) conversion program.

METHODS

The prospectively collected Children's Memorial Hermann Heart Institute Society of Thoracic Surgeon's Database was retrospectively reviewed between July 2017 and July 2020.

RESULTS

Thirteen patients met inclusion criteria and underwent BiV conversion during that time. The most frequent diagnosis was malposed great arteries and a ventricular septal defect (VSD) in 4 (31%) patients. Seven (54%) patients were in the first interstage, and 1 (8%) patient had already undergone a Fontan operation before their BiV conversion operation. One or more risk factors for single ventricle palliation (genetic syndrome ≥ moderate atrioventricular valve regurgitation ≥ moderate ventricular dysfunction, presence of signs of Fontan failure) were present in 3 (23%) patients. The median left ventricular end diastolic pressure increased from 5.5 mmHg (4-10 mmHg) to 10 mmHg (6-20 mmHg) postoperatively (p < .05). The right ventricular pressure (RVP) was estimated as less than half systemic in all six patients who were able to be estimated. At a median follow-up of 22.6 months (0.3-36.4 months), 12 (92%) patients are alive.

CONCLUSIONS

BiV conversion is feasible with reasonable short-term clinical outcomes. Mortality risk is low, but as seen in other studies, the risk of reintervention is high.

Can Left Atrioventricular Valve Reduction Index (LAVRI) Predict the Surgical Strategy for Repair of Atrioventricular Septal Defect?

Despite improved survival, surgical treatment of atrioventricular septal defect (AVSD) remains challenging. The optimal technique for primary left atrioventricular valve (LAVV) repair and prediction of suitability for biventricular approach in unbalanced AVSD are still controversial. We evaluated the ability of our recently developed echocardiographic left atrioventricular valve reduction index (LAVRI) in predicting LAVV reoperation rate and surgical strategy for unbalanced AVSD. Retrospective echocardiographic analysis was available in 352 of 790 patients with AVSD treated in our institution and included modified atrioventricular valve index (mAVVI), ventricular cavity ratio (VCR), and right ventricle/left ventricle (RV/LV) inflow angle. LAVRI estimates LAVV area after complete cleft closure and was analyzed with regard to surgical strategy in primary LAVV repair and unbalanced AVSD. Of the entire cohort, 284/352 (80.68%) patients underwent biventricular repair and 68/352 (19.31%) patients underwent univentricular palliation. LAVV reoperation was performed in 25/284 (8.80%) patients after surgical correction of AVSD. LAVRI was significantly lower in patients requiring LAVV reoperation (1.92 cm²/m² [IQR 1.31] vs. 2.89 cm²/m² [IQR 1.37], p = 0.002) and significantly differed between patients receiving complete and no/partial cleft closure (2.89 cm²/m² [IQR 1.35] vs. 2.07 cm²/m² [IQR 1.69]; p = 0.002). Of 82 patients diagnosed with unbalanced AVSD, 14 were suitable for biventricular repair (17.07%). mAVVI, LAVRI, VCR, and RV/LV inflow angle accurately distinguished between balanced and unbalanced AVSD and predicted surgical strategy (all p < 0.001). LAVRI may predict surgical strategy in primary LAVV repair, LAVV reoperation risk, and suitability for biventricular approach in unbalanced AVSD anatomy.

Trisomy 21 Patients Undergoing Cavopulmonary Connections Need Improved Preoperative and Postoperative Care

BACKGROUND

Patients with trisomy 21 (T21) often have elevated pulmonary vascular resistance, which may result in a suboptimal cavopulmonary connection (CPC) after a Glenn or Fontan operation. The purpose of this study was to assess, in a nationwide, multiinstitution cohort of patients with CPC, the impact of T21 on patient morbidity, mortality, and resource use.

METHODS

A total of 23,271 pediatric patients with CPC (2004 to 2019) at 50 US hospitals were evaluated using the Pediatric Health Information System database. Univariable and multivariable regression analyses were used to assess risk-adjusted associations between Down syndrome and other risk factors and postoperative measures of morbidity, mortality, lengths of stay, and cost of hospitalization.

RESULTS

The overall prevalence of T21 among patients who had undergone Glenn and Fontan procedures was 1.5% (199 of 13,268) and 0.8% (78 of 1003), respectively. Among both CPC cohorts, T21 status significantly increased unadjusted mortality, hospital lengths of stay, and total costs of hospitalization compared with the non-T21 CPC cohort (all P < .001). Patients with T21 also had a higher incidence of prolonged mechanical ventilation compared with patients without T21 in both Glenn and Fontan groups (P < .001). Multivariable regression analysis further estimated that patients with T21 are associated with a 5.5-fold increase in mortality (P < .001) compared with patients without T21. Finally, patients with T21 had increased long-term mortality compared with their peers.

CONCLUSIONS

T21 significantly increases risk-adjusted morbidity, inpatient mortality, long-term mortality, and resource use after cavopulmonary connections. Further investigation is needed to clarify modifiable patient-level and center-specific risk factors to improve outcomes for patients with T21.

Double atrioventricular valve replacement using Melody™ transcatheter valves in an infant with unbalanced atrioventricular septal defect: a case report

Background

To the best of our knowledge, this is the first report of a successful one-stage double atrioventricular valve (AVV) replacement using two Melody™ transcatheter valves in an infant.

Case summary

We report a successful case of double AVV replacement with Melody™ transcatheter valves in a 9-month-old infant with a right ventricular dominant atrioventricular septal defect (AVSD). The boy initially presented with borderline sized left-sided heart structures, congenital left AVV stenosis, ventricular displacement of the right AVV with high-grade insufficiency and moderate valvar pulmonary stenosis. Double AVV replacement was performed 2 months after an unsuccessful attempt to repair the defect with persisting left AVV stenosis, underfilling of the small left ventricle and high-grade right AVV, and pulmonary valve regurgitation, resulting in low cardiac output. During double Melody™ AVV replacement, the right ventricular outflow tract was replaced with a pulmonary homograft. The boy was discharged on post-operative Day 28 and presented with competent valves, no ventricular outflow tract obstruction and no paravalvular leak at 11 months of follow-up.

Discussion

The presented innovative approach allowed for biventricular correction of an unbalanced AVSD with unfavourable anatomy for standard techniques. The heart team should decide individualized, after careful assessment of cardiac anatomy and function, if the benefits of replacement of AVVs with Melody™ transcatheter valves may outweigh the benefits of univentricular palliation in case of unbalanced AVSD.

Biventricular Conversion in the Borderline Hypoplastic Heart

PURPOSE OF REVIEW

The development of biventricular repair and conversion pathways for patients with borderline hypoplastic heart disease represents an area of recent inquiry and innovation. This review summarizes emerging techniques and novel treatment algorithms for borderline hypoplastic heart disease with a focus on surgical advances within the last 10 years.

RECENT FINDINGS

Many patients with borderline hypoplastic heart disease are amenable to primary biventricular repair, or biventricular conversion following single-ventricle palliation coupled with ventricular rehabilitation strategies. New insights into the potential for growth and recovery of borderline ventricles have been uncovered. However, questions remain regarding optimal patient selection and the long-term outcomes of select patient groups treated with single-ventricle palliation versus biventricular repair/conversion or transplantation. Efforts to direct a greater proportion of borderline hypoplastic heart patients towards a biventricular circulation are accelerating and represent important avenues for progress and future research in the field of congenital heart disease.

Outcomes of Common Atrioventricular Valve Repair in Patients With Single-Ventricle Physiology - Indication, Timing and Repair Techniques

BACKGROUND

Common atrioventricular valve (CAVV) repair in patients with a single ventricle remains a great challenge and a refractory issue for pediatric cardiac surgeons. Methods and Results: From January 2007 to April 2018, 37 consecutive patients with a single ventricle who underwent CAVV repair were included in the study group. Patients were divided into 2 groups based on the repair technique: patients in Group A were treated using the bivalvation technique, and patients in Group B underwent conventional repair techniques; baseline data were similar between groups. The inhospital and follow-up mortality were 5.4% (2/37) and 11.4% (4/35), respectively. After a follow-up of 65.5±29.3 months, the estimated 1-, 5-, and 10-year overall survival rates were 94.6%, 83.4%, and 77.0%, respectively. The rates of freedom from CAVV failure were 94.3%, 72.7%, and 62.9% after 1, 5, and 10 years, respectively. In the multivariate analysis, the independent factors for CAVV repair failure were repair technique (P=0.004) and heterotaxy syndrome (P=0.003). A total of 30 patients (81.1%) completed total cavopulmonary connection (TCPC); 3 patients required re-intervention; 24 of 31 patients (77.4%) were in New York Heart Association classes II and I at the latest follow-up.

CONCLUSIONS

Outcomes of CAVV repair in patients palliated by single-ventricular surgery are acceptable. The bivalvation technique is a simple and effective technique.

Recent advances in managing septal defects: ventricular septal defects and atrioventricular septal defects

This review discusses the management of ventricular septal defects (VSDs) and atrioventricular septal defects (AVSDs). There are several types of VSDs: perimembranous, supracristal, atrioventricular septal, and muscular. The indications for closure are moderate to large VSDs with enlarged left atrium and left ventricle or elevated pulmonary artery pressure (or both) and a pulmonary-to-systemic flow ratio greater than 2:1. Surgical closure is recommended for large perimembranous VSDs, supracristal VSDs, and VSDs with aortic valve prolapse. Large muscular VSDs may be closed by percutaneous techniques. A large number of devices have been used in the past for VSD occlusion, but currently Amplatzer Muscular VSD Occluder is the only device approved by the US Food and Drug Administration for clinical use. A hybrid approach may be used for large muscular VSDs in small babies. Timely intervention to prevent pulmonary vascular obstructive disease (PVOD) is germane in the management of these babies. There are several types of AVSDs: partial, transitional, intermediate, and complete. Complete AVSDs are also classified as balanced and unbalanced. All intermediate and complete balanced AVSDs require surgical correction, and early repair is needed to prevent the onset of PVOD. Surgical correction with closure of atrial septal defect and VSD, along with repair and reconstruction of atrioventricular valves, is recommended. Palliative pulmonary artery banding may be considered in babies weighing less than 5 kg and those with significant co-morbidities. The management of unbalanced AVSDs is more complex, and staged single-ventricle palliation is the common management strategy. However, recent data suggest that achieving two-ventricle repair may be a better option in patients with suitable anatomy, particularly in patients in whom outcomes of single-ventricle palliation are less than optimal. The majority of treatment modes in the management of VSDs and AVSDs are safe and effective and prevent the development of PVOD and cardiac dysfunction.